Engineer&#39;s. brake-valve



J'. W. BINGLEY.

ENGINEERS BRAKE VALVE.

APPLICATION FILED AUG.4, 1920.

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JOHN w. antenna', or WATE'RTOWN, Newman, nssreuoa 'ro man NEW Yoan I BRAKE COMPANY, A. CORPORATION NEW YOR.

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y Speeication of Letters Patent.

Application sied august e, 1920. serial ne. 401,241..

To aZZ 'wlwm t may concern.'

Be it known that 1, JOHN W. Brunner, a citizen ofi the United States, residing at Watertown, in the county of Jefferson, kand State of New York, have invented c ertain new and -useful Improvements in Engineers? Brake-Valves, of which the following isa specification. 'A

This invention relates to air brakesand particularly to an engineers brakev valve iiitended primarily for use with automatic train stop systems.

The object of the invention is to provide van improved pressure motor so related to the rotary valve, forming apart of the usual engineers brake valve, as to-move said rota valve to service application' position anldlbring it to rest, so that it may be moved thereafter to emer ency position byhand.

A valve motor o this general type isdescribed and claimed in my prior application SerialNo. 132,873, filed November 22, 1916, and consequently certain features of the motor and valve claimed in the prior application are described in the present application but are not claimed herein. n

The present invention adds to the prior device a novel -form of pneumatic check, designed to` insure that the brought gently to rest when the valve rea-ches service application' osition. Y While the valve of my prior app ication operates satisfactorily, it is Ifound that when the motor and valve have been' used for a considerable period, and hence operate quite freely, there is a tendency for the mechanism to lover-travel, the rotary valve frequently moving by its acquired momentum past serv; ice position vto emergency position. While in longitudinal axial section; In this View' the valveis vin release'position. v

Fig. 2 is a similar view showing the valve moved to service application position by the motor, and

Fig. 3 is an enlarged fragmentary view 56 similar to-Fig. 2, and showing the relation of motor will be this action can 'be prevented by proper ad-v the piston andpiston rod to the piston checking` ports.

he valve is intended chiefly for use with engineers brake valves of the equalizing discharge type. rilhese commonly have sixpositions known as release, holding, lap, service, and emergency positions. The successive positions of the valve handle are indicated by legends on Fig. 1. .The removable cap forming part of the casing.. of anordina engineers brake valve is indicated at 6. qt is held to the body of the valve casing by bolts 5. The handle of the brake valve is shown at 7, th

handle detent at 8', and the detent sector at 9. All of the above mentionedparts willbe recognized as of ordinary construction with the exception of minor additions to the cap and the handle, which will be described later.A

Formed on the cap 6 is a boss 10 to which is bolted a horizontal cylinder 11. -This cylinder is closed at one end by a removable head 12, and is formed at the o posite end with a closely ttin guideway or the`pis:

ton rod.v The cylin er-ll hasnear its head end a tapped opening to receive the pressure fluid pipe 13 which communicates with thev head-end pressure port 14.- Thepipe 13 is connected with a source of. pressure fluid, andthe flow of pressure fluid is controlled byv anyy suitable means, for example, by a valve forming part of any automatic train stop mechanism. A iston 15 provided with piston rings 16 is s idably mounted in the cylinder 11. Usually the rings 16 do not vfit so tight as to preclude lslig t leakage of pressure past-the piston, and this leakage is availed o when vthe pressure supply is cut o Such leakage is far less than the capacity .of port 14, and hence is insui'icient to interfere withA the uaction of the motor when pressure fluid is admitted thereto. Any equivalent means for venting pressure from the motor, such for example as a small leak Aport Y(not shown) leadingfrom port 14 tothe atmos- .phere might be adopted. The pistonv 15 abuts-a inst a piston rod 17 but is not con-` nected t creto, Therod. 17 is guided in the end of the cylinder'll and' is connected to a laterally ,oset rack 18, which is guided lin a guideway 19 formed in the side ofthe cylinder 11. The rack 18 meshes with'a sector gear 2O formed on the handle 7,

runningfi to relieve the cylinder of ressure Patented Mai. i, 192i.

iooI

The partsso far described do not differ" in any essential particular from the structure of my prior application. In my former construction I made use of a port s1m1- 5 lar to port 21lof the present device to relieve the pressure behind piston 15, when the piston moves outward under pressure entering through port 14. The port 21- 0f the present application is, however, preferably made smaller than the corresponding port of my prior construction, and 1n addltion to the port 21 I provide a supplementary port 22 of equal, or preferably greater, capacity. The port 22 is formed through the side of the cylinder 1 and so positioned as to be operative throughout' the initial movement of the piston from its inert position. The port 22 is, however, blanked by the piston 15 when this aproaches the end of its travel and remains Elanked by the piston 15 thereafter.

The effect of this construction is to allow the piston to move very rapidly at first and then to check the piston by checking the bleeding of' pressure fluid from the spa-ce behind the piston. By making the port 21 small this checking action can be made quite severe. As the piston 15 closely approachesits' final limit of travel and after its motion has been sharply checked, it 1s desirable to release the air trap ed behind 4it more rapidly than by. liow t rough the port 21. Accordingly I form inthe piston rod 17 a grooved port 24 which opens communication with a relatively large feed port 23 just before the piston 15 reaches its limit of travel. This insures complete travel.

The operation of the device is as follows: Assume that the train is in:I motion and about the tlme it reaches lap position, the' piston 15 will blank port 22. v The air behind piston 15- can now escape only through the restrictedport 21'. This causes a marked retardation of the piston 15, which thereafter completes its travel slowly, moving the valve through lap to service position. Just as the valve-'reaches service position the port 24 becomes effective Ato bleed any remaining back pressure through port 23, and thus insures full travel of thepiston 15.

It is thus-possible to move'jthe handle 7 to vservice application positionwith the utthat the valve handle is in release position' Amost rapidity and' without danger that it The main advantage of the constructionl described is, the possibility of much more rapid action in moving the brake handle to service position, without danger of overthrowing the handle because the motor piston is checked in time to permit the handle detent to function with certainty. The device also has the advantage, characteristic of my prior construction, that the frictional load of the piston is not imposed on the valve handle 1n ordinary manual operation, while all other moving parts of the mechanism are constantly actuated durin the manual operation of the valve, thus insuring that t ey will never be stuck or inoperative when needed.

What is claimed is:

1. The combination Aof an engineers brake valve; a pressure-motor operatively related to said valve, and including a cylinder and a piston working therein; and a pneumatic check vservmg to retard said piston near the Aenel of its operative stroke.`

2. The combination of an engineers brake valve; a pressure-motor operatively related to said valve, and including a cylinder and a piston working therein; and a pneumatic check serving to retard said piston and including ports whose effective area is diminished by the Aapproach of the piston to the end of its operative stroke.

3. The.combination of an engineers brake valve; a pressure-motor operatively related to said valve and including a cylinder and a piston wor 'n therein; and a back-pressure device for c ecking said iston, and including bleed ports controlle` by the piston near t e end of the operative stroke of the latter.

4. The combination yof an engineers brake valve; a pressure motor including a cylinder and a piston working therein; a piston-rod serving as an operative connection between said motor and valve; and a back-pressure device. for checking said iston and including bleed-ports, one of w ich is blanked by the iston in the latter art of the operative stro re thereof and anotlibr of which 1s closed by said piston-rod throughout' substantially the entire operative stroke of saidpiston and is opened by saidy rod in the limiting-position of said piston.

5. The combination of an engineers brake part of the operative stroke thereof2 and anvalve; a pressure-motor including a cylinder other of which is closed by said plston-rod and a piston Working therein; a piston rod throughout substantially the entire operaoperatively connected with said valve, and tive stroke of said piston, and is opened by 5 adapted to be engaged and moved bysaid said rod in the limiting position of said 15 piston when the piston is forced froml its piston. normal retracted position; and a back-pres- 1n testimony whereof I have signed my sure device for checking said piston and name to this specification. including bleed-ports, one of which is 10 blanked by said piston in the latter JOHN W. BINGLEY. 

